Zwitterionic polymers are widely recognized for their exceptional antifouling performance; however, integrating zwitterionic functionality into polyurethane while retaining mechanical robustness and processability remains a significant challenge. Addressing this gap, we introduce a versatile design strategy for synthesizing zwitterionic polyurethanes that integrate both zwitterionic diol and triol precursors, enabling long-term antifouling performance and tunable physical properties. We report the synthesis of a new class of poly(carboxybetaine hexamethylene urethane) (PCBHU) prepared through step-growth polymerization of carboxybetaine (CB)-based diols/triols and aliphatic diisocyanates, followed by controlled ester hydrolysis to generate zwitterionic groups along the polymer backbone. The formation of densely hydrated CB moieties establishes a strongly bound hydration layer that governs the antifouling behavior. The resulting materials exhibit excellent thermal stability, with degradation temperatures above 200 °C, and well-defined thermal transitions characterized by TGA and DSC. By varying the soft-to-hard-segment ratio, we achieved precise control over mechanical properties and water uptake, revealing clear structure-property relationships within this zwitterionic PU platform. Importantly, the PCBHUs markedly suppress nonspecific protein adsorption, mammalian cell adhesion, bacterial attachment, and biofilm formation, demonstrating durable antifouling performance far superior to conventional polyurethanes. The synthesis route is simple, scalable, and compatible with existing PU manufacturing, enabling these PCBHUs to serve as drop-in replacements for commercial polyurethane lacking antifouling functionality. This strategy provides a practical and broadly applicable approach for endowing polyurethane-based biomaterials and medical devices with long-lasting antifouling properties.

While thioether linkages are commonly associated with soft and amorphous polymer backbones, herein, we show that a calcium carbide-derived α,ω-bis(vinylthio) synthon enables crystalline, sequence-defined sulfur polymers with nonconventional luminescence. A single-step thiol-yne addition reaction uses acetylene generated in situ from industrial calcium carbide (CaC2) to produce a modular C2 vinyl sulfide (also known as vinylthio) monomer that undergoes quantitative, light-induced thiol-ene step-growth polymerization with aliphatic dithiols. Type I photoinitiation ensures complete anti-Markovnikov addition to give C2 -segmented poly(thioether)s, while thermal and base-mediated conditions generate hybrid poly(thioether)/polydisulfide structures. The resulting sulfur-rich backbones display sharp melting transitions, spherulitic crystallization, one-step thermal decomposition up to about 316°C, and pronounced cluster-triggered emission arising from dense thioether clustering and through-space conjugation. Green metric analysis reveals high Atom Economy and essentially waste-free polymer formation, thereby linking efficient use of an established C2 synthon to precision sulfur polymer design. This C2 vinylthio platform provides a general strategy to convert classically soft thioether motifs into structurally ordered and luminescent materials, and establishes vinyl sulfides as powerful, yet underutilized, building blocks in sustainable polymer chemistry.

The increasing incidence of breast cancer is leading researchers to investigate new treatment approaches. Targeted therapy approaches are particularly attractive because they minimize the detrimental effects of therapeutic agents on healthy tissues and cells by focusing on tumor sites. This study focuses on synthesizing mPEG-modified triblock copolymers as carrier materials for drug delivery applications, enabling the efficient encapsulation of DOX, and evaluating the cytotoxic effects of the resulting nanocarriers on breast cancer cell lines. In this study, mPEG-poly(butylene adipate)-mPEG and mPEG-poly(ethylene adipate)-mPEG triblock copolymers were synthesized by a step-growth polycondensation polymerization method. Firstly, poly(butylene adipate) (pBAd) and poly(ethylene adipate) (pEAd) were synthesized to form the body of the triblock copolymer, and their chemical structures were characterized using Fourier transform infrared (FT-IR) and 1H NMR spectroscopy. The end-group analysis method was applied to determine the average molecular weights of the pBAd and pEAd polymers before their modification with mPEG-500. The nanocarriers produced by the double emulsion method were analyzed using the dynamic light scattering (DLS) method, while encapsulation efficiency and the DOX release profile were measured using a spectrofluorometer. The antiproliferative effects and cellular uptake capacities of the resulting nanocarriers were subsequently examined in MCF-7 and MDA-MB-231 cells. The cytotoxicity of DBANP and DEANP nanocarriers was lower than that of free DOX, demonstrating that encapsulation reduces drug-associated toxicity and may enhance safety. These findings suggest that the nanocarrier systems developed in this study show strong potential as promising candidates for breast cancer therapy.

We present the scalable, additive-free synthesis of polymer nanoparticles in continuous flow, using solely solar radiation. Using a custom-made flow reactor, the UV radiation from the sun induces a Diels-Alder step-growth polymerization between a bismaleimide and a difunctional o-methylbenzaldehyde. The resulting photopolymer subsequently precipitates as nanoparticles without the need for any additional additives, stimuli or processing steps. The solar flow reactor was designed by first carefully assessing the underpinning photochemistry of the photo-induced Diels-Alder reaction using photochemical action plots and then performing a kinetic investigation of the particle formation under solar irradiation. The determined kinetics allow us to extrapolate our experimental results to a worldwide particle yield by using global UV index data, validated by two highly different geographical locations, Australia and Germany. Our results clearly demonstrate the applicability of our system for the scalable, sustainable, solar-powered production of polymeric nanoparticles in regions of high levels of solar radiation. Furthermore, our calculations function as a blueprint for how local experimental data can be extrapolated to assess the global solar photochemical potential of photochemical systems, thus making their performance comparable.

Photoinduced step-growth polymerizations are an important avenue to soft matter materials. However, photopolymerizations are highly challenging to unpack into their individual reaction steps and to determine the efficiency of these individual steps as a function of wavelength. Herein, we introduce a combined synthetic and photochemical action plot methodology to isolate the two key reaction steps of a step-growth photo-Diels-Alder polymerization and independently map their wavelength-dependent quantum yields with monochromatic resolution. To characterize our system with the highest possible precision, we introduce a photochemical action plot method based on the absorption of a constant number of photons at each wavelength. Our specific photopolymer system is based on a bis-o-methylbenzaldehyde (oMBA) species where the two reaction sites are electronically connected. Our approach initially entails the selective synthesis of a mono-Diels-Alder adduct from the symmetrical difunctional oMBA, enabling the precise mapping of the blue-shift in wavelength-dependent reactivity between the first and second addition. Our final molecule represents a distinct system of five fused rings, which matches the macromolecular system.

Elemental sulfur (S8), an abundant petroleum byproduct, is leveraged as a linchpin monomer in an organobase-catalyzed step-growth addition polymerization with dithiols and diacrylates at ambient temperature. This method enables the scalable synthesis of poly(ester disulfide)s-featuring alternating ester and disulfide linkages-with exceptional atom economy ( > 95% yield), Mn up to 42.0 kDa, and dual functionality: biodegradable ester units and stimuli-responsive disulfides. Mechanistic studies reveal a chemoselective three-component coupling involving S8 ring-opening, disulfide anion formation, and Michael addition, quantitatively generating symmetric and asymmetric disulfides in near-equimolar ratios. Thermal and mechanical characterizations of the poly(ester disulfide)s reveal programmable properties: High thermal stability (Td,5% = 248-281 °C), tunable phase behavior (amorphous Tg = -64 °C to semicrystalline Tm = 142 °C), and reductive degradation. By overcoming traditional limitations of harsh conditions and monomer scope, this strategy establishes S8 as a versatile feedstock for functional polymers, opening avenues for dynamic materials in biomedicine and environmental remediation.

Bottom-up tissue engineering has gained significant interest for its ability to recreate the complexity of human organs by assembling functional tissue units through techniques such as extrusion-based bioprinting (EBB). To enable the future biofabrication of human-scale organs, new bioinks for EBB must be developed that facilitate the formation of a functional vascular network within the biomaterial. Without a vascular system, high cell densities within the construct struggle to survive due to the diffusion limits of oxygen and nutrients. Additionally, the bioink must exhibit sufficient printability to accurately recreate the 3D CAD model. In the current work, elastin is modified with norbornene groups to enable step-growth polymerization with thiolated gelatin, resulting in a novel hybrid biomaterial. Unmodified gelatin and porogens are incorporated into the elastin-gelatin hydrogel to enhance printability in EBB and increase porosity, respectively. When only unmodified gelatin is added to the elastin-gelatin hydrogel, shape fidelity on a continuous platform is excellent, and the bioink successfully bridges gaps up to 8 mm with a 100% success rate. Upon addition of alginate gel porogen (AGP), quality of printing on a continuous platform is maintained, but the gap-bridging capability becomes limited to gaps smaller than 4 mm. Nonetheless, the elastin-gelatin hydrogel supplemented with both unmodified gelatin and AGP is preferred, as it promotes superior vascular development compared to a wide range of other bioinks, with vasculogenesis-driven self-assembly of embedded endothelial cells reaching a total vascular network length of 26 ± 6 mm mm-3and angiogenic sprouting from vascularized spheroids reaching a total sprout length of 4 ± 2 mm within the hydrogel by day 7. A bioink that supports this level of vascular development while maintaining sufficient printability represents a valuable addition to the toolkit for bottom-up tissue engineering using EBB.

In lithography-based additive manufacturing, step-growth polymerization is a highly desired mode as the resulting polymer networks are usually more homogenous and therefore tougher than ones obtained by free radical chain growth polymerization. Therefore, thiol-ene chemistry sees widespread use, however, the employed thiols are accompanied by strong odor, limited availability and limited storage stability of the formulation. Replacing the thiols with alcohols resolves these problems as a wide variety of odorless alcohols is available. The oxa-ene reaction presented here is a base-catalysed Michael-type reaction for which a highly active Lewis base catalyst is known. Our work shows the preparation of photocaged Lewis base catalysts for this oxa-Michael addition, its implementation into photochemistry and the accompanying new mechanism compared to the regular thermal catalysis. Additionally, the storage stability of such formulation was investigated at different temperatures. Finally, the developed system is applied in additive manufacturing using hot lithography approaches with both linear and non-linear absorption of light.

Growing application of magnetic thin films and inductor chips for analog circuits in voltage regulators, mobile phones, MEMS and defense sector technologies rise need for new alloys and structures with low energy losses during electromagnetic induction process. Miniaturization of the new thin film inductor devices requires that these alloys and structures have the highest possible magnetic moment and resistivity to achieve high specific inductance and minimum permeability loses related to Eddy currents.We present work on development of electrodeposition process for 2.2-2.4 T CoFeX alloys and CoFeX/X laminated structures from single solution chemistry. They show no permeability decrease over the wide frequency range up to 0.5 GHz. This is achieved by alloy bulk resistivity control adding a resistivity controlling element in the alloy X (X=O, P, C) and introducing a resistive barrier layer with electrochemical lamination to control the alloy laminate thickness to be below the alloy skin depth. Therefore, achieving the structures with complete suppression of Eddy currents for inductor devices with lossless induction process. The schematics of the deposition process is shown in Figure 1A. The one-laminate deposition includes a cycle consisting of two stages: (a)-CoFeX-alloy deposition (t1, j1) and (b)-electro-polymerization stage (PPY resistive barrier, t2, E=-0.75 V). The process is repeated arbitrary number of times to create laminated structure with desired thickness. The representative data are shown in Figure 1B. The permeability and quality spectra from cavity induction measurements illustrate advantage of laminated structures over the bulk thin film alloy. Figure 1. (A) Schematics of the laminate synthesis via electrodeposition and electro- polymerization steps. (B) Permeability and Q spectra from cavity measurements for thin film CoFeX alloy and CoFeX/X laminated structure. Insets show surface morphology of electrodeposits. Figure 1

Abstract We report here how the polymerization‐induced self‐assembly approach can be implemented in orthogonally reactive dispersants to afford the preparation of nanostructured polymer networks. Precisely‐defined PMMA ‐b‐ PLMA block copolymers self‐assembling into different morphologies are first obtained in epoxy monomers through RAFT dispersion polymerization. The subsequent polymerization of the epoxide (through step growth or chain growth polymerization) affords the straightforward preparation of epoxy networks that integrate diverse BCP structures and exhibit significantly enhanced fracture toughness at extremely low block copolymer content (1% w/w).

We report here how the polymerization-induced self-assembly approach can be implemented in orthogonally reactive dispersants to afford the preparation of nanostructured polymer networks. Precisely-defined PMMA-b-PLMA block copolymers self-assembling into different morphologies are first obtained in epoxy monomers through RAFT dispersion polymerization. The subsequent polymerization of the epoxide (through step growth or chain growth polymerization) affords the straightforward preparation of epoxy networks that integrate diverse BCP structures and exhibit significantly enhanced fracture toughness at extremely low block copolymer content (1%w/w).

Flow RAFT Step-Growth Polymerization

Polymerization is a fundamental process in polymer science that underpins the synthesis of materials used across diverse industrial and technological sectors. This review provides a comprehensive examination of the two principal polymerization mechanisms—step-growth and chain-growth polymerization—highlighting their distinct reaction pathways, kinetics, and structural outcomes. In step-growth polymerization, monomeric units bearing complementary functional groups combine gradually, often producing small by-products, and requiring high monomer conversion to achieve high molecular weights. Conversely, chain-growth polymerization involves the rapid addition of monomers to an active centre, enabling the formation of high molecular weight polymers early in the reaction. The review explores subtypes such as radical, anionic, cationic, and coordination polymerizations, detailing their initiation, propagation, and termination steps. Special emphasis is placed on photo polymerization as a modern approach enabling spatial and temporal control in polymer synthesis, particularly in applications like 3D printing and micro fabrication. The comparative analysis also discusses the thermodynamic and kinetic considerations, reaction conditions, and practical applications of each method. Overall, this review aims to offer a consolidated understanding of polymerization mechanisms, serving as a valuable reference for students, researchers, and professionals involved in polymer chemistry and materials science.

ABSTRACTConventional chain-growth polymerization of acrylic monomers or diacrylics leads to non-degradable vinyl polymers or crosslinked networks, while existing step-growth polymerization affords saturated or main-chain unsaturated polyesters, hindering post-functionalization. Here, we introduce a hydrogen-transfer polymerization (HTP) strategy via the trialkylphosphine-catalyzed head-to-tail C–C coupling between the α- and β-positions of two vinyl groups of diacrylates with exclusive regioselectivity, producing unsaturated polyesters with side-chain double bonds that can undergo the subsequent thiol-Michael click reaction in a one-pot fashion with the carryover phosphine from the HTP step. The resulting hydroxyl-functionalized polyesters serve as macroinitiators for the efficient synthesis of densely grafted poly(l-lactide) (PLLA) bottlebrush polymers. Such bottlebrush polymers markedly toughen the otherwise brittle PLLA (by ∼10×), while not only uniquely preserving high melting temperature and crystallinity of PLLA but also synergistically increasing the PLLA crystallization rate.

Abstract New series of aromatic poly(ether ether ketone imide)s were synthesized from 1,3-bis-4-(4″-aminophenoxy benzoyl) benzene and aromatic dianhydrides such as BTDA, PMDA. BPDA, HFDA, OPDA, by two step polymerization method. Starting materials and difficulties in synthesis or processing, relatively few of these polymers achieved commercially viability. These poly(ether ether ketone imide)s were characterized by FT-IR, Solubility, Inherent viscosity, TGA, DSC and XRD. Inherent viscosities of these poly(ether ether ketone imide)s were in the range of 0.23–0.40 dL/g in DMF, indicating formation of moderate molecular weight of polymers. Currently there is lot of difficulties to synthesize processable polyimides due to hard, rigid, bulky nature it become more drastic to process polymers. We were synthesized polyimides showed good solubility in polar aprotic solvent due to incorporation of functional moiety such as ether, ketone, flexible linkages in the backbone of polymer chain rather than aromatic polyimides. poly(ether ether ketone imide)s showed good solubility in polar aprotic solvents such as N,N-dimethyl acetamide (DMAc), N-methyl 2-pyrrolidone (NMP), N,N,-dimethyl formamide (DMF), and Dimethyl sulphoxide (DMSO). These poly(ether ether ketone imide)s had glass transition temperatures; as determined by DSC, in the range of 241–270 °C. These polymers showed similar decomposition patterns and had no weight loss below 235 °C and temperatures for 10 % weight loss (T10) were in the range of 269–370 °C, indicating that these polymers showed good thermal stability and degradation at 800 °C indicating its sustainability. As per the TGA data char yield of these synthesized poly(ether ether ketone imide)s were very low char yield or residual weight of polyimides at 700 °C temperature indicates low limiting oxygen index value that is more flammable and sustainable polymers.

Graft polymers with degradable backbones and preciselytunableside chains are highly desirable for advanced functional materials,particularly in biomedical and stimuli-responsive systems. Herein,we report a versatile strategy to synthesize degradable graft polymersvia a reversible addition–fragmentation chain transfer (RAFT)step-growth polymerization approach using bifunctional poly­(methylacrylate) (PMA) macromonomers and a bifunctional vinyl monomer. Thepolymerization proceeds through an A2 + B2-typepolymerization mechanism, wherein the steric hindrance from macromonomersis effectively alleviated by incorporating a small-molecule RAFT agentas a comonomer. The resulting graft copolymers exhibit tailorableside-chain lengths and tunable rheological properties. Notably, thepolymer backbones feature dual stimuli-responsive degradability enabledby xanthate and ester linkages, allowing stepwise degradation viaaminolysis and hydrolysis. Furthermore, RAFT functionalities embeddedin the backbone allow postpolymerization chain expansion, offeringcontrol over both the backbone architecture and graft density. Thiswork provides a modular and robust platform for engineering degradablegraft polymers with programmable architectures and multifunctionalitysuitable for applications in drug delivery and smart materials.

This study investigates the impact of graphene oxide (GO) nanoparticles on the physical, chemical, and mechanical properties of random polyesters. The nanocomposites were synthesized using a step-growth polymerization technique, incorporating varying concentrations of GO (1%, 2%, and 3%). Mechanical tensile testing, thermal analysis, and X-ray diffraction (XRD) were performed to assess the performance of the prepared samples. The results revealed that a low concentration (1%) of GO significantly enhanced the mechanical properties and thermal stability of the polyester matrix, in addition to improving its crystalline structure. Conversely, higher concentrations (2% and 3%) led to nanoparticle agglomeration and a noticeable decline in both mechanical and thermal performance due to poor dispersion within the polymer matrix. These findings underscore the importance of optimizing filler content to improve composite properties and support their potential application in biomedical and electronic fields.

Intramolecular cyclization is a pervasive yet often ignoredfactorin step-growth polymerizations (SGPs), particularly under dilute conditions.While experimental studies have confirmed the significant impact ofconcentration on cyclization, the lack of deep theoretical understandinghas limited the ability to guide reaction design and predict the polymerstructure. In this work, we adopt a reverse-engineering strategy toextract cyclization-related equations from experimental data usinga classical A2 + B2 step-growth polymerization system. By combininganalytical derivations with symbolic regression, a machine learningtechnique for generating closed-form expressions, we obtain explicitformulas for cyclization probability, degree of cyclization, degreeof linear polymerization, and molecular weights as functions of monomerconversion and reaction concentration. These expressions capture thedynamic nature of cyclization and demonstrate excellent agreementwith experimental results across a broad concentration range. Ourwork provides a new quantitative framework to incorporate cyclizationinto SGP theory and offers practical tools for predicting molecularstructures and properties under real-world conditions.

In this study, polyesters synthesized from AB Tung oil-based polyols (TOBPs) monomers via step-growth polymerization reactions. TOBPs are polyols made from Tung oil through a series of hydroxylation and epoxidation procedures. They have hydroxyl (OH) and carboxylic (COOH) functional groups. The polymerization was performed in a three-necked round-bottomed flask (250 mL) equipped with a magnetic stirrer, thermometer, and condenser. It is placed in an oil bath to maintain the reaction temperature. The generated moisture was collected using a vacuum pump. In the meantime, oxygen is being expelled from the reactor by nitrogen. The temperature and stirring speed were kept constant for 6 hours throughout the operation. According to the experiment, 150°C was the ideal temperature for polyesterification. The reaction rate constant rose by 4.73 to 19.99% with the addition of the p-TSA catalyst. The [COOH] and [OH] models were nearly identical to the experimental results, demonstrating the viability of the proposed kinetic model. According to the calculation's findings, polymerization without a catalyst yielded activation energies (Ea) and collision factors (A) of 27.2215 kJ/mol and 16.2965 g.mmol-1.min-1, respectively. Then, polymerization with catalyst decreased Ea and A values, which were around 26.4681 kJ/mol and 14.6746 g.mmol-1.min-1. Copyright © 2025 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Thermoresponsive hydrogels that undergo reversible sol-gel transitions near physiological temperatures are highly attractive for biomedical applications, such as injectable drug delivery and embolization therapies. In this study, a library of polyurethane-based hydrogels was synthesized via step-growth polymerization using polyethylene glycol (PEG) of varying molecular weights, different diisocyanates, and a series of functional diols derived from diethanolamine with increasing hydrophobicity. The resulting polymers exhibited sol–gel transition behaviors without the need for external crosslinkers, relying solely on non-covalent interactions. The thermal responsiveness was systematically investigated using UV–Vis turbidimetry, and the cloud point temperature (TCP) was found to be tunable within a range of 26–49 °C by modulating the monomer composition. Statistical modeling identified PEG molecular weight and diol structure as the primary determinants of TCP, while diisocyanate type and diol-to-PEG ratio had negligible effects. Only diethanolamine (DEA)-based polymers formed stable hydrogels above a critical gelation temperature (LCGT), attributed to enhanced intermolecular interactions via free amine groups. In vitro degradation assays confirmed good hydrolytic stability under physiological conditions over four weeks, with degradation profiles strongly influenced by the PEG chain length and hydrophobic content. These findings establish a structure–property framework for the rational design of injectable, thermoresponsive polyurethane hydrogels with tailored sol–gel behavior for biomedical applications.